STOICHIOMETRY

STEPS

100

What is the first step you take when doing stoichiometry?

Write the balanced equation.

200

What is the second step you take in stoichiometry?

List your 'known' and 'unknown' information

300

What is the third step you take in stoichiometry?

Identify conversion factors

400

What is the last step in stoichiometry?

Check and round off your answer

500

What is something you could use to help you with the stoichiometry process?

Simplify the question and write only the needed information i.e values

CONVERSIONS

100

What are you trying to find when you convert moles to moles?

The Mole Ratio.

200

What are you trying to find when you convert moles to grams?

Molar Mass.

300

For the combustion of methane:

CH₄+2O₂→CO₂+2H₂O 

If you have 4 moles of oxygen gas, how many moles of water will be produced?

4 moles of H₂O

400

A balanced chemical equation for the combustion of propane is: 

         C₃H₈+O₂→CO₂+H₂O

                     C₃H₈+5O₂→3CO₂+4H₂O

500

Fe+O₂--->Fe₂O₃

Find the mole ratio of Iron to Oxygen

4:3

DEFINITIONS

100

What is Stoichiometry?

Mass relationships between substances in a chemical reaction.

200

What do we look at to find mole ratios?

The coefficients in a balanced equation.

300

How do we determine the gram-per-mole (g/mol) value of an atom?  

• Find the atomic mass of the element on the periodic table.
• Express the value in g/mol (since atomic mass units (amu) and g/mol are equivalent in magnitude).

400

The reaction between magnesium (Mg) and oxygen (O₂) to form magnesium oxide (MgO) is what type of chemical reaction?

Combination (Synthesis) Reaction

500

when a hydrocarbon reacts with oxygen  producing carbon dioxide and water, a ______ type of reaction take place.

Combustion Reaction

MOLE ISLAND

100

Calculate the molecular mass or formula mass of KCl

74.55 g/mol

200

What is Avogadro's number?

6.02x10^²³

300

How do we convert moles to grams?

Multiply by molar mass.

400

What are you calculating for if you divide by 6.022x10^23 then multiply by molar mass?

Converting from particles to grams

500

How many atoms are in 1 gram?

6.02 × 10²³ 

PROBLEMS

100

Fe₃O₄ + 4 CO--->3 Fe + 4 CO₂

How many moles of CO are needed to react with 

16.5 g of Fe₃O₄?

0.285 moles CO

200

How many moles of Fe₂O₃ will form from 5.0 moles of Fe?

2.5 moles

300

How many moles of KClO₃ must decompose in order to produce 9 moles of oxygen gas?

6 moles KClO₃

400

How many grams of NaCl will be produced from 1.25 mol of chlorine gas reacting with sodium?

146 g

500

Ammonium nitrate (NH₄NO₃)decomposes into dinitrogen monoxide(N₂O) gas and water (H₂O). Determine the amount in grams of water produced if 25.0 g of ammonium nitrate decomposes.

11.3grams H₂O